Automatic stop device for strip-inserting mechanism of power presses



Nov. 6 1923. 1,472,802

- C.D.MDONALD AUTOMATIC STOP DEVICE FOR STRIP'INSERTING MECHANISM OF POWER PRESSES Filed Jan. 20, 1923 s Sheets-Sheet 1 Nov. 6 1923.

c. D. M DONALD AUTOMATIC STOP DEVICE FOR STRIP INSERTING MECHANISM OF POWER 'PRESSES 3 Sheets-Sheet 2 Filed Jan. 20, 1923 Z6 5 f/f 20/164267 Nov. 6, 1923. 1,472,802

C.D.MCDONALD AUTOMATIC STOP DEVICE FOR STRIP INSERTING MECHANISM OF POWER PRESSES Filed Jan. 20, 1923 3 Sheets-Sheet 5 57/67Z/0 7; C/wZes Fifi/604.7 7,

Patented Nov. 6, 1923.

warren stares iaiaeez CHARLES D. MCDONALD, OF CHICAGO, ILLINOIS.

AUTOMATIC STOF DEVICE FOR STRIF-INSERTING MECHANISM OF POWER PRESSES.

Application filed January 20, 1923. Serial No. 613,808.

T 0 all whom it may concern Be it known that 1, CHARLES D. MCDON- ALI), a citizen of the United States, and a' resident of Chicago, Cook County, and State of Illinois, have invented certain new and useful Improvements in Automatic Stop Devices for Striplnserting Mechanism of Power Presses, of which the following is declared to be a full, clear, and exact description.

This invention relates to automatic stop devices for the strip inserting mechanism of power presses, and its primary object is to provide a simple, efficient and practical device for arresting the movement of the strip inserters, (which insert the strips into the feed slot) in case a strip is not in the proper position to be inserted at the time that the strip inserters are actuated. The invention has been designed for use in connection with automatic power presses, and it sometimes happens in machines of this kind that the suction cups, or other means for lifting the metal strips one at a time, become inoperative, so that the strip is not moved to the proper position for insertion into the feed slot. The work is then apt to be jammed when the strip inserters engage the work, which makes it necessary to stop the press, thereby causing loss of time and loss of material. One object of this invention is to provide means, operating under the influence of the strips themselves, to arrest the movement of the strip inserters unless a lifted strip is in proper position to'be inserted into the feed slot. It sometimes happens that one of the several suction cups, or other strip lifting device, becomes temporarily inoperative, with the result that one end of the strip is permitted to sag, whereas the other parts of the strip are held in proper position for insertion into the feed slot, and one object of this invention is to provide automatic means operating to arrest movement of all of the strip inserters in case either of the end suction cups or other strip lifting devices, becomes'inoperative and fails to lift either end of the strip into proper position for insertion in the feed slot- Other objects and advantages will occur in the course of this specification and with all of said objects and advantages in view, this invention consists in a device for arresting movement of the strip inserters and having means operated by a properly lifted strip, to permit the strip inserters to function. It further consists in a stop device for the strip inserters having a movable dog normally located in the path of movement of a moving element of the strip. inserting mechanism, and means associated with the end suction cups or other strip lifting devices, and operated by a properly lifted strip to move the dog out of the path vof movement of said movable element of. the strip inserting mechanism. It further consists in a plurality of movable dogs normally located in the path of movement of the end strip inserters and having members, one associated with eachsuction cup, or other strip lifting device, for moving the associated dog out of-the path of movement of the strip inserters whenever the strip is lifted into proper position for in sertion into the feed slot. It further consists in the several novel features hereinafter fully set forth and particularly defined in the claims. 7 v

The invention is clearly illustrated in the accompanying drawings, in which:

Fig. 1 is a side elevation of an automatic power press equipped with an, automatic stop device for the inserting mechanism, embodying a. simple form of the present invention; Fig- 2 is a front view ofthe said press mechanism looking in the direction of the arrow 2 in Fig.1; F ig..3 is a detail, front view of one of the suction cups, the associated strip inserter and the associated stop device, showinng the parts in position when a strip has been lifted into proper place for insertion into the feed slot; Fig. 4 is a view similar to Fig. 3 but showing the stopdevice in another position and Fig. 5

is a plan of the parts seen in Fig. 3 with.

the suction cup stem shown in cross section.-

Referring to said drawings, which illustrate the invention applied to an automatic power press similar to the press shown in several of; the prior patents on thepresses issued to the McDonald Machine CO. and in my prior Patent No. 1,039,565 dated September 24, 1912, the reference character 10 designates the power press mechanism,:11 the table upon which the strips a of metal or other work is laid and from which the strips are lifted one at a time and thereafter inserted through afeed slot 13 into position to be fed to the dies in a step by step manner; 12 designates the feed bar which feeds the inserted strips to the dies; 14, 14 designate the suction cups or other strip lifting devices; 15, 15 designate stems which carry said suction cups; 20 a rod or bar connected to the stems of the several suction cups; 21 a link; 19 a lever connected to said link and 18 a link connected to the other end of the lever and to a crank wheel 17 which is driven by the power mechanism of the press. The suction cup stems 15, 15 are guided in bearing brackets 16 mounted on the frame of the press. A vacuum is created in the suction cups at the time they engage the strips and said vacuum is broken when the suction cups reach the upper limits of their strokes, and said vacuum is produced by a vacuum pump connected by a flexible tube 20 the rod 20 and stems 15 (which are tubular) to the suction cups.

1 Adjacent the end suction dups 14 are the strip inserters or strip inserting arms 50, which have rods 40 that are slidably mounted in bracket 4t) mounted on the frame of the press, and said strip inserting arms are reciprocated in timed relation to the movement of the suction cups, by mechanism, here shown as comprising collars 44 secured on the rods 40' of the strip inserting arms, links 42 connected to said collars, rocker arms 41 connected to said links, a rock shaft 45 on which said rocker arms 41 are secured, a rocker arm 41 onthe rock shaft 45,21 rocker member 46 connected to said rocker arm 41 by a link 47 and a cam 48 cooperating with a roller 46 on said rocker member 46 tomove the inserting arms back after they have performed their work. A spring 49 secured to the press frame and to the rocker arm 41 imparts the working strokes to the strip inserting arms. All of the mechanism thus far described is common and well understood and is more fully set forth in detail in many of the prior patents above referred to, and requires no further detailed description so far as this specification is concerned. It will be understood from the above that at the time that the strips are lifted to a position in line with and in front of the feed slot, the roller 46 of the rocker member 46 runs off the high part of the cam 48, and the spring 49 thereupon moves the rocker arm 41 and therewith the rock shaft 45, rocker arms 41 and links 42, bringing the strip inserting arms 50 into engagement with the edge of the lifted strip, and forcing said strip into the feed slot 13, in position to be acted on by the feed mecha nism.

Located in the path of movement of one of the moving elements of the strip insertmechanism is a stop device, normally acting to arrest movement of said moving element and having means associated with each end suction cup for moving said stop device out of the path of movement of said moving element of the strip inserting mechanism whenever a stip is lifted into proper position for insertion into the feed slot. In the specific form of the invention illustrated in the accompanying drawings, the stop mechanism comprises dogs 51, one pivotally mounted upon each end suction cup guide bracket 16, to move in a vertical plane. As shown, studs screws 52 pivotally secure each dog upon the guide bracket. One end of each dog projects beyond its bracket 16 and is located in the path of movement of the collar 44 of the associated strip insert-er, as is clearly seen in Fig. 4. Movement of the strip inserter in the direction of the arrow in Fig. 5 is arrested by the dog 51 whenever it is in the operative position in Fig. 4.

Associated with each dog 51, is a dog actuating member which, as illustrated;

comprises a pin 53 slidably mounted in a bearing bracket 54 which issecured to the associated suction cup guide bracket 16, and said pin has a collar 55 secured thereon at a place adjacent its upper end, which collar normally rests upon the top of the bracket 54 and supports the pin therein. The free end of the pin 53 engages with the under side of the dog 51. and forms the support for the free end thereof. when moved upward by any force, the collar 55 rests upon the bracket 54 and supports the pin in the position seen in Fig. 4 where its upper end supports the free end of the dog 51 in a position located in the path of travel of the collar 44. The collar and dog may have correspondingly beveled portions 56, 56 to facilitate themovement of the collar past the dog when being re turned to its outer position after having performed its work. When the pin is supported by the collar. its lower end projects a short distance below the lower face of the suction cup 14, as seen in Fig. 4 and when moved upward, (until the lower end' of the pin. is flush with the lower face of the suction cup,) it raises the free end of the dog 51 out of the path of. travel taken by the collar 44, thereby permitting said collar and therewith the strip inserter to move in a direction to insert a properly lifted strip into the feed slot. Fig. 3 shows a strip alifted by the suction cup. into proper position where it may be inserted into the feed slot by the strip inserter 50. It will be clearly seen from an inspection of this figure that by reason of the engagement of the lifted strip a with the bottom of the Except pin 53, the latter has been raised and therewith the dog 51 has been moved upward out of the path of travel of the collar 44-.

In the opera-tion of the device, the suction cups lift the strips 0. one at a time, and when the suction cups are working normally, they lift the strip into a position in line with the feed slot 13, after which the roller d6: of the strip inserting mechanism runs off the high part of the cam 48, and the spring 49 edge of the strip and forces the strip into the feed slot. In case either endsuction cup fails to function properly when it is lifting a strip, and as a consequence permits one of the ends thereof to sag, that end of the strip fails to engage and raisethe pin associated with said suction cup, thereby permit-ting the associated dog 51 to remain in its operative position obstructing movement of an associated strip inserting arm. Inasmuch as the strip inserting arms at both ends of the feed table are fixedly connected to the rock shaft 45, both strip inserting arms are prevented from moving in case one or the other of them is prevented from so moving. In this condition, when the roller 4C6 runs off the high part of the cam 48, the spring 49 merely pulls upon the rocker arm tl but inasmuch as neither strip inserting arm is capable of any movement, the parts remain neutral, thereby permitting the improperly lifted strip to fall back upon the pile of strips. In case the suction cups fail to properly function during the next cycle of operation, the press is stopped and the necessary repairs are made.

More or less variation of the exact details of construction is possible without departing from the spirit'of this invention; I desire, therefore. not to limit myself to the exact form of the construction shown and described, but intend, in the following caims, to point out all of the invention dis closed herein.

I claim as new and desire to secure by Letters Patent:

1. In a power press, the combination of strip lifters, strip inserting mechanism operating to insert a lifted strip into a feed slot of the press, and control means for said strip inserting mechanism, having a stop member normally located in the path of a moving element of said strip inserting mechanism, and strip actuated elements associated with the strip lifters and arranged to move the stop member out of the path of movement of said moving element of the strip inserting mechanism, whenever actuated by a lifted strip.

2. In a power press, the combination of strip lifters, strip inserting mechanism having strip inserting arms, and control means for said strip inserting arms, said controi means having a stop member located in I whenever said means is the path of movement of a moving element of said strip inserting mechanism,-and strip actuated elements arranged to move the stop member out of the path of movement of said moving element of the strip inserting mech-- anism, whenever actuated by a lifted strip.

In a power press, the combination of suction cups, strip inserting arms associated there ith, mechanism for simultaneously 'moving said arms, and arm arresting dogs? moves the strip inserting arms against the one associated with each suction cup and arm, and normally located in position to arrest movement ofan associated arm, each dog having strip actuated means for moving said dog out of its effective position, actuated by a lifted strip. Y i 4-. In a power press, the combination of suction cups, strip inserting arms associated therewith, each arm having a collar thereon, mechanism for simultaneously moving said arms, and arm arresting dogs, one associated with each suction cup and arm, and normally located in position to engage the collar of an associated arm, and thereby arrest movement of an associated arm.

5. In a power press, the combination of suction cups, strip inserting arms associated therewith, mechanism for simultaneously moving said arms, arm arresting dogs, one associated with each suction cup and arm, and normally located in position to arrest movement of an associated arm, strip actuated, dog engaging pins, one pin for each dog, operating to move said dog out of its effective position whenever the pin is actuated by a lifted strip.

6. In a power press, the combination of suction cups, strip inserting arms associated therewith, there being a collar on each arm, mechanism for simultaneously moving said arms, arm arresting dogs, one associated with each suction cup and arm, and normally located behind an associated collar in position to arrest movement of an associated arm, and strip actuated, dog engaging pins, one pin for each dog, operating to move said dog out of its effective position whenever the pin is actuated by a lifted strip.

7. In a power press, the combination of suction cups, strip inserting arms associated therewith, mechanism for simultaneously moving said arms, arm arresting dogs, one associated with each suction cup and arm, and normally located in position to arrest movement of an associated arm, a bracket,

strip actuated, dog engaging pins, one pin,

for each dog, and a collar secured on each pin and normally resting on a bracket, and supporting one end of the pin in the path of movement of the strips.

8. In a power press, the combination of two suction cups, two strip inserting arms, one associated with each suction cup, arm actuating means having one element to which both arms are fixedly connected, arm arresting dogs, one associated with each suction cup and arm and lying in the path of movement of a fixed part of an associated arm, and a strip actuated, dog lifting pin for each dog operating to lift said dog out ofits effective position.

9; In a power press, the combination of two suction cups, two strip inserting arms, one associated with each suction cup, arm actuating'i'neans having one element to which both arms are fixedly connected, said actuating means including a yielding arm actuating element, arm arresting dogs, one associated with each suction cup and ar n, and lying in the path of movement of a fixed part of an associated arm, and a strip masoa actuated, dog lifting pin foreach dog, operating to lift said dog out of its eflective position.

10. In a power press, the combination of two suction. cups, two strip actuating arms, one associated with each suction cup, there being a collar on each arm, arm actuating means having one element to which both arms are fixedly connected, said actuating means having a yielding, arm actuating element, arm arresting dogs, one associated with each suction cup and arm and lying in the path of movcment'of the collar on an associated arm, and a strip actuated, dog lifting pin for each dog, operating to lift said dog out of its efiective position.

CHARLES D. MCDONALD. 

